Valve device for anesthesia systems and respirators

ABSTRACT

A valve device specifically for anesthesia systems and respirators, etc., comprising a check valve in a one-way system conveying breathing air to and from a patient as well as additional components, if desired, such as oxygen and/or anesthetic agent. The valve utilizes a balloon or bladder which releases the system air etc. to the outside through an appropriately designed balloon support when an overpressure occurs in the balloon as the result of excess pressure of said system air etc.

United States Patent VALVE DEVICE FOR ANESTHESIA SYSTEMS AND RESPIRATORSl 1 Claims, 16 Drawing Figs.

U.S. Cl...; 128/l45.7, 128/188 lnt. Cl ..A61m 17/00 Field ofSearch128/145],

202,145.5,l45.6,145.8, 188; 137/525,155,4 96; 25l/61.l

[56] References Cited UNITED STATES PATENTS 2,268,145 12/1941 Welty128/202 2,737,176 3/1956 Fox l28/l45.8 2,907,322 10/1959 Hay 128/14563,286,710 11/1966 Bartlett 128/1455 Primary ExaminerRichard A. GaudetAssistant Examiner-G. F. Dunne Attorney--Woodhams, Blanchard and FlynnABSTRACT: A valve device specifically for anesthesia systems andrespirators, etc., comprising a check valve in a one-way systemconveying breathing air to and from a patient as well as additionalcomponents, if desired, such as oxygen and/0r anesthetic agent. Thevalve utilizes a balloon or bladder which releases the system air etc.to the outside through an appropriately designed balloon support when anoverpressure occurs in the balloon as the result of excess pressure ofsaid system air etc.

PATENTED Aum 7 19m 3599.634

SHEET 1 0F 5 Fig.1 (2) PRIOR ART PRIOR ART PATENTED AUG] 7197! SHEET 2UF 5 Fig.1.

PRIOR ART PATENTED AUG 1 7:971

SHEET U [1F 5 VALVE DEVICE FOR ANESTHESIA SYSTEMS AND RESPIRATORSBACKGROUND OF THE INVENTION 1. Field of the Invention This inventionrefers to apparatus and systems for administering anesthesia in surgery,and specifically to a valve device in a breathing apparatus included insuch systems. The invention may also find application in such breathingapparatus as respirators etc.

2. Description of the Prior Art As is well known, anesthesia inconnection with surgery has the purpose of providing the brain with awell-balanced dose of anesthetic. This is conveyed to the brain throughthe blood,

' which in turn is provided with the anesthetic by direct injection intothe blood vessels (intravenous anesthetic) or by inhaling vaporizedso-called inhaling anesthetics and diffusion of the latter to the bloodin the lungs. In certain types of surgery it is necessary to make thepatients musculature relax. This is achieved either by deeper anesthesiaor by a muscle relaxing agent (for example curari) being injected intothe blood vessels. The latter method necessitatesartificial'respiration, asv the breathing musculature also will becomeparalyzed.

One of the tasks of the personnel administering anesthetics is toobserve the blood circulation and the respiration. As is well known, thenormal respiration has the purpose of providing the body' with oxygenand of eliminating carbon dioxide, which is expelled from the bodythrough the lungs. The hygienic side of this includes making itnecessary to ascertain that infections are not transferred fromcontaminated, i.e. unclean, anesthetic equipment.

The anesthetic systems that are in present day use operate well andreliably, but they are nevertheless subject to certain drawbacks. Forone thing they require experience with respect both to their generalmanipulation and to the setting of valve devices included therein, whichrequire uninterrupted attention. For another thing, cleaning andsterilizing their vital components are exceedingly laborious andtime-consuming processes. After a completed administration of ananesthetic the equipment must be washed, dried and processed in anautoclave before it can be utilized for the next patient.

SUMMARY OF THE INVENTION The object of this invention is to provide abreathing apparatus for anesthetic systems, in which the drawbacksindicated above are reduced to a level that may well be accepted inpractice or entirely obviated, by performing an important valve functionin a novel manner and by means of a novel valve device. The object ofthe invention is achieved and a breathing apparatus that is easilyhandled and that operates reliably is provided by the valve device ofthe invention being given the features disclosed in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS A number of embodiments of theinvention will now be described so as to illustrate the same withreference to the accompanying drawings, in which:

FIG. I is a diagrammatic illustration of a modern anesthetic system ofconventional design.

FIGS. 2 and 3 illustrate the manner of operation of the system inaccordance with FIG. 1 in inhaling and exhaling, respectively.

FIG. 4 is a diagrammatic cross section of a semiautomatic breathingbellows of the Air Shield type.

FIG. 5 is a cross section through the support means disclosed by theinvention for a breathing balloon.

FIGS. 6 and 7 are cross sections along the lines Vl-VI and VII-VII,respectively, of FIG. 5, and FIG. 7a is a cross section corresponding toFIG. 7 but through a modified support means.

FIG. 8 is a cross section through an additionally modified design of thesupport means of FIG. 5.

FIG. 9 is a view, partially in section, along the line IX-IX of FIG. 10,through an additionally modified embodiment of the support means, and rp FIG. 10 is a cross section along the line X-X of FIG. 9.

FIG. 11 is a cross section through a second embodiment of I theinvention and illustrates a support means for a breathing balloonprovided with an internal discharge tube with a valve plate. I

FIG. 12 is a partial cross section along the line XII-XII of DESCRIPTIONOF THE PREFERRED EMBODIMENTS In order to facilitate the comprehension ofthe invention the principle design of a typical breathing apparatus in amodern anesthetic system and its mode of operation will be disclosedbriefly by manner of introduction with reference to FIGS. 1-

4, respectively. Thus the breathing apparatus 10, see FIG. 1, comprisesa channel system or a conduct system in communication with the patientand forming a one-way closed path of flow for the breathing gas mixtureconsisting of air, supplementary oxygen and anesthetic gases. The pathof flow comprises a branch pipe 12, through which the gas is conveyed toand from the patient, respectively, over a close-fitting face mask or aso-called tracheal tube (a sterile rubber tube iritroduced .into thewindpipe with a seal against its interior by means of an inflatablerubber sleeve). Two corrugated rubber tubes 14 extend from the branchpipe 12, and one of these, viz 14a, conveys the expiratory gas to anabsorbing unit 16 containing calcium for absorbing carbon dioxide. Theinlet side of said unit is provided with a check valve I8, and a similarcheck valve 20 is positioned behind the unit. From the latter checkvalve the gas is conveyed through the second rubber tube 14b back to thebranch pipe 12. The conduit system joining the outlet of the absorbingunit 16 to the check valve 20 is provided with an outlet having a softrubber balloon 24 (volume 24 liters, i.e. 2.24.4 quarts) connectedthereto.

If the system is considered thus far, it will immediately be seen thatthe two check valves force the oxygen, to flow around in a closedcircuit, constantly in the direction indicated by the arrows; Whenexhaling occurs, the gas will flow along the upper path (in accordancewith FIG. I) and will pass the absorber l6 and will fill the balloon 24.In subsequent inhaling, the upper path will be blocked, and the gas willflow through the check valve 20 and the tube 14b back to the patient. Arepeated cycle of this type with the breathing gas traveling between thelungs of the patient and the balloon 24 will naturally create a lack ofoxygen concurrently with car- 7 gas mixture from the portioning meansbeing conveyed to a 5 nipple or similar connection 28 in the conduitsystem 22 between the absorber l6 and the balloon 24 over a tubeconnection.

As the closed system continuously is supplied with an addition of gas,corresponding gas discharge of equal quantity must be provided so as tocomply with the continuity principle without an overpressure occuring inthe system. For instance,

this may be carried out by a spring actuated relief valve or leak valve,diagrammatically indicated at 30, being introduced into thecommunication between the upper rubber tube 14a and the check valve I8at the inlet of the absorber. The overpressure valve 30 is set to adefinite position so as to be opened in response to a slightoverpressure occuring at the termination of the expiratory phase forexpelling the appropriate amount of gas from the system for maintaininga continuous steady state.

FIGS. 2 and 3 diagrammatically illustrate an inhaling and exhalingsequence, respectively In inhaling, the valve 20, see

FIG. 2, is opened, and the breathing gas from the balloon 24 will flowtogether with a continuous addition from the external gas source throughthe connection 18 to the patient through the lower tubel4b and thebranch pipe 12. Both the check valve 18 and the leak valve 30 are nowclosed. During the exhaling phase, see FIG. 3, the check valve 18 isopened, whereas valve is closed, and the gas will flow from the branchpipe 12 through the rubber tube 14a and the absorbing unit 16 to theballoon 24 for filling the latter. Towards the end of the exhaling aslight pressure increase will occur as the result of the counterpressurein the balloon24, and hence the leak valve will open and will release anexcess quantity of the gas corresponding to the continuous externaladdition through the connection 18.

In modern breathing apparatus of the pertinent type it is also possibleto perform overpressure breathing or artificial respiration whennecessary, when the patient is not capable of breathing spontaneously.The breathing balloon 24 is then subjected to an external rythmicpressure applied either by the anesthetic administrator compressing itmanually or with the assistance of mechanical or pneumatic means,thereby urging the gas contents of the balloon 24 into the lungs of thepatient along the path shown in FIG. 2. When the balloon is released orunloaded, exhaling occurs, thereby inflating the balloon, thusmaintaining the breathing. I

As has been mentioned above the relief valve 30 must be set to adefinite position, particularly for providing an appropriatedistribution of gas between on one hand the lungs of the patient'and onthe other hand the valve itself for discharge during artificialrespiration. This demands both skill and experience in the personadministrating the anesthetic. Other relief valves of semiautomatic typehave been proposed, and, in particular, the rubber balloon 24 has beenreplaced by'a corrugated rubber bellows, the movements of which control,a discharge valve or leak valve in different ways (for instance in knownsystems of the Air Shield type or the Spiropulsator type). As a finalexample of conventional methods FIG. 4 diagrammatically illustrates oneof these breathing bellows of the Air Shield type.

A corrugated bellows 32 is positioned in a closed housing 34 having abottom 36 provided with a circular neck portion 38, to which the bellows32 is fastened as the figure illustrates. The neck portion 38 isprovided with an inlet 40 to the bellows trol a leak valve device inwhich the balloon itself is included as a valve element that closes andopens discharge .flow channels from the balloon. This design providessome analogy to the bellows 32 accordance with FIG. 4 inasmuch as a gasdischarge occurs at the end of an exhaling phase, but the simplificationis extremely broad and there are no valve mechanisms nor movablecomponents at all apartfrom the rythmically pulsating balloon.

For the purpose of the invention two individual portions of the balloonmay be utilized, viz either its neck portion or the tip portion or endportion opposite thereto. FIGS. 5-10 illustrate some embodiments of thefirst type, whereas FIGS. 1 1- 13 show examples of utilizing the endportion of the balloon as valve means. 7

The designation 54 in FIG. 5 refers to a portion of the upper wall of ahousing or protective cover having appropriate form and accommodating abreathing balloon 70. A balloon socket 58 is introduced into an aperture56 in' the wall 54 and is detachably and sealingly affixed in theopening in a manner not disclosed in detail, for instance by means of abayonet mount or similar. The socket 58 comprises a'substantiallycylindrical device that is adapted to support the balloon 70, the neckportion 700 of which is provided with a bulge 70b along itsupper edge inconventional manner, with said bulge being received in a circumferentialgroove 59 at the upper part of the cylindrical portion of the socket 58as illustrated in FIG. 5. Below the bulge 70b the neck portion 70a ofthe balloon follows close to the cylindrical socket 58, i.e. inrelieved, nonextended condition the internal diameter of the neckportion very nearly conforms with the external diameter of the socketand therefore the balloon neck will surround and lightly contact thesocket without substantial stretch. The

. neck 70a is slightly longer than the portion of the socket 58 situatedbelow the balloon bulge and extends outside of this portion,subsequently expanding outwards.

The portion of the socket 58 enclosed by the balloon neck 70a isprovided with a number of axial grooves 60, see FIGS. 5

and communicates with the patients lungs substantially in the connection42. The portion of the bellows 32 opposite to the neck portion 38 isclosed by means of an endpiece 44. One' end of a light chain 46 isfastened to said endpiece 44, and the other end of said chain isconnected to an exhaling valve 48 having the form of a valve cone orvalve hall 50 disposed to close an outlet 52 in the neck portion 38. asis diagrammatically indicated in FIG. 4. During exhaling, when thebellows 32 expands and the endpiece 44 withdraws from the neck portion38, the chain.46 will be extended so as to remove the ball 50 from itsseat and to release the excess of breathing gas through the outlet 52towards the end of the exhaling. Hence, the exhaling valve 48 serves inthe same manner as the leak valve 30 disclosed above.

In accordance with the basic principle of the invention a breathingballoon substantially of the type 24 illustrated in FIGS. l-3,respectively, is utilized in such manner that is movements, i.e.alternating expansion and contraction, conand 7, respectively, uniformlydistributed along the circumference of the socket. The grooves 60 beginsomewhat inside of the lower axial end of the socket, as seen in FIG. 5,and they terminate with their upper ends in a comparatively deep,circumferential groove or an annular groove 62 shortly below the balloonbulge groove 59. From the interior of groove 62 a number of channels 64extend upwards through the socket 58 so as to terminate in theatmosphereoutside of the balloon housing. A centrally located inlet channel 66extends through the socket 58 from an upper tube or pipe connection 68,which only has been illustrated diagrammatically, to a lower, expandedchannel portion 66a terminating in the interior of the balloon 70.

The groove system 60-62-64 together with the balloon neck 70a forms acheck valve device, which in principle may be compared to the valve of abicycle inner tube. When the patient exhales, the balloon 70 is filledand expanded in normal manner. Towards the termination of theexhaling-the balloon material is stretched and the neck portion 70a isalso expanded so as to be displaced from the cylindrical socket 58, asindicated by dotted lines in FIG. 5, thereby opening a passage to theoutside through the axial grooves 60, the annular groove 62 and thechannels 64, so as to discharge the excess of gas this'way instead ofthrough formerly used valves, particularly leak valves, for instance thevalve 30 in accordance with FIGS. l3. The path of flow is indicated bydot-dashed arrows in FIG. 5.

Hence, in order to openthe discharge passage, a certain overpressure inthe balloon is necessary, and the magnitude of this overpressure isprimarily determined by how snugly the balloon neck encloses the socketand by the thickness of the balloon material. The design of the socketmay also influence the opening pressure. FIG. 8 illustrates a modifieddesign 58' of the socket, wherein its lower portion, which receives theballoon neck, has conical shape and is either convergent or (indicatedbydashed lines) divergent downwards. The balloon downwardly convergingsocket, axially extending the balloon as the result of inflating thesame will contribute to displacing theneck from the socket.

The balloon socket may also have polygonal cross section or it may beprovided with flattened portions in which the discharge grooves areformed, for instance as illustrated by the socket 63 of FIG. 7a. Thissocket has a hexagonal cross section with rounded corners, and grooves61 have been formed in the six flat surfaces 65 as illustrated by thefigure. The balloon neck 71 encloses the socket 63 lightly butsealingly, and with this design the necessary pressure increase in theballoon for displacing the neck of the latter from the socket so as todischarge gas will be still smaller. The conical sockets 58' inaccordance with FIG. 8 may also be provided with flattened surfacescarrying the grooves 60'.

FIGS. 9 and 10 illustrate an additional modification 58" of the balloonsocket This socket is designed in the same manner as socket 58, but itis provided with an additional number of axial grooves 72 in theenvelope surface of the socket between the .valve grooves 60". Theadditional grooves 72 are somewhat wider and shallower than the grooves60", and in contrast to the latter they begin at the lower end of thesocket 5 8" and terminate shortly below the annular groove 62". In thiscase the balloon neck 70"a is preformed with inwardly directed folds'74,which are received in the grooves 72 with tolerances as illustratedin.FIG. 9 and 10,- respectively. The

purpose of these folds is to lower the opening pressure, i.e. the

overpressure in the balloon that is necessary for opening the dischargepassage through the socket. :Therefore it is not necessary in this casethat the material of the neck portion 70"a of the balloon be stretchedso as to displace the rubber from the socket but merely that the folds74 be straightened out to a greater or smaller extent. 7 7

FIGS. ll13 illustrate some examples of the second method of theinvention as disclosed above for utilizing the breathing balloon as avalve device, specifically the portion thereof opposing its neck portionor end portion. In this case a balloon socket 76 is provided, which isintroduced into an aperture in the upper wall 78 of a balloon housing.The lower or inner portion of the socket is designed in appropriatemanner'and is provided with a bulge groove 77 for fastening the neck ofa rubber balloon 80 provided with a bulge 80b. The inlet to the balloonconsists of a nipple 82 being affixed in the side of the socket 76 andbeing' connected to the remainder of the breathing apparatus by means ofa tubular connection that is not specifically illustrated. A dischargetube 84. thatis threaded externally at the top is centrally located inan opening. in socket 76 provided with internal threads and may be;adjusted vertically by rotating a knurled finger grip 86 provided at theupper end of the tube. The inner or lower end of the tube is slightlyexpanded and is provided with a fixed, somewhat curved valve disc 88having apertures 90. The discharge tube 84 extends through the entireballoon 80and engages the end portion 80:: thereof, withthe balloonbeing maintained substantially extended by the tube so-that the end Iportion 80a will cover the apertures 90and will lightly engage thecurvedvalve disc 88. The arrangement should be clear from FIG. 11.

With 'exhaling, the balloon is expanded in normal manner, andwhen theballoon materialhas been stretched its'end portion 800 will disengage;the valve disc 88, thereby positioning the balloon 80 as illustrated bydashed lines in-FIG. 1'1 so that excess gas will be expelledthroughapertures 90 into tube 84 asindicated by the arrows. In order to offerless resistance at the-initial fillingthe balloon may appropriatelyhave'the form of a flattened rubber bladder in its empty state inwell-known manner, as illustrated by the cross section'of FIG. 12, andit may even be provided with a fold as illustrated at 800 in the samefigure.

by a resilient counteracting component as is diagrammaticallyillustrated in FIG. 13. The counteracting component 94,

which is disposed adjustably in the bottom 79 of the balloon housingcoaxially to the discharge tube 84, may for instance consist of a bowl95 turned upside down and having an exter-- nally concave bottom whichis shaped in conformance with the curved valve disc 88' and is lightlyurged against the latter by a compression spring 96, the compression ofwhich may be adjusted by means of a small knob 98, as may be seen fromthe figure without more specific description. In this case the balloondoes not have to be maintained stretched for engagement against thevalve disc 88 and instead it may be entirely loose and freein its emptystate, with the exception of the actual end portion 80'a, which ismaintained lightly urged against the valve disc 88' by the counteractingcomponent 94 and covers the openings of said valve disc. The balloon maybe ventilated more thoroughly by means of this supplementingcounteracting component device, but the function is the same as in theembodiment of FIGS. 11 and 12, respective- Iy. I

In conclusion, FIGS. 14 and 15 illustrate how a breathing apparatusprovided with the valve device of FIGS. 5 or 9, respectively, operates.With inhaling, see FIG. 14, the sequence will be substantially the sameas is illustrated by FIG. 2. The breathing gas flows from the balloon 70together with an addition from the connection 28 through the openingcheck valve 20, the lower, corrugated rubber tube 14b and through thebranch pipe 12 to the lungs of the patient. In this operation theballoon neck tightly encloses the discharge grooves 60 (see FIG. 5) ofthe socket 58, and neither air nor other gas can penetrate from theoutside this way. With exhal ing, see FIG. 15, the gas flows from thelungs of the patient through the branch pipe 12, the upper tube 14a, theopening check valve 18, the Co -absorber l6 and to the balloon 70. Thelatter expands, and in the final stage the lower part of its neckportion releases its engagement with the socket 58, with the excess gasflowing out through the latter, as has been disclosed previously. InFIG. 15 dashed lines illustrate a simple device by means of which themoment of opening the balloon valve may be influenced. An adjustableplate 102 is displaced upwards towards the balloon from the bottom 79 ofthe balloon housing and engages the lower end of the balloon. The higherthe plate 102 is displaced, the earlier will the valve open.

respiration mentioned by way of introduction, i.e. whenthe patientcannot breath spontaneously, the balloon 7.0 is subjected to a rythmicexternal pressure which urges its contents to the lungs of the patient.In order to provide a' respirator, i.e.

an apparatus for pure breathing systems, the absorbingunit' 16' isdisconnected and the patient is made to breath out'dire'ctly into theatmosphere by means of an appropriate exhaling valve-at his mouth.Concurrently, a partial vacuum-is created outside the balloon 70' sothat atmospherical-air willbe'dr'awn An important advantage in theinvention is that certain of-its embodiments, particularly thoseillustrated'as examples in FIGS. 5-l0,nrespectively, as the result oftheir simplicity are attractive as embodiments foruse one single time,i.e. theballoon and its associated socket may be manufacturedas'aisimple unit in mass'production that'may be thrown away after'u'se.

For providing the overpressure breathing or artificial The invention isnaturally not limited to the embodiments illustrated and describedabove, and it may be varied in additional respects within thescope ofthe basic conception of the invention.

1 claim:

1. In a breathing apparatus having a one-way closed flow circuit and astorage balloon'or bladder connected to the circuit for momentarilyaccumulating and storing herein the breathing gases discharged from apatient, means for adding a supplement, such as oxygen or an anestheticagent, to the gases stored within the balloon, whereby said gases in theballoonare then supplied to the patient, said balloon including a neckportion having an opening therein and support means disposed within saidopening for supporting said balloon, the

edge of said balloon as defined by said opening being in engagement withsaid support means, and said support means having opening meansextending therethrough forproviding communication between said circuitand the interior of said balloon whereby breathing gases can be suppliedto or withdrawn from said balloon, the improvement comprising:

relief means for permitting external discharge of excess gases from saidballoon during expansion of the balloon when the pressure of the gaseswithin the balloon exceeds a predetermined maximum; said relief meansincluding discharge passage means formed in said support means forpermitting discharge of said excessgases to a location external of saidballoon, said I discharge passage means having an inner end adapted forcommunication with the interior of said balloon; and said balloon havinga movable wall portion normally disposed in sealing engagement with aportion of said support means for preventing communication between theinterior of said balloon and the' inner end of said discharge passagemeans whe'n'the pressure within said balloon is less than saidpredetermined maximum; whereby exceeding said predetermined maximumpressure during expansion of said balloon causes said, movable wallportion to move out of sealing engagement with said support means forpermitting the excess gases to flow through said discharge passagemeans. I i I 2. An apparatus according to claim 8, wherein said supportmeansincludes a substantially cylindrical support member disposed withinthe neck portion of said balloon, and said discharge passage meansincluding a discharge passage formed within. said support'member andextending substantially therethrough, the inner end of said dischargepassage terminating at the outer periphery of said support member at alocation which is spaced. from the inner end, of said support member,and said neck portion of said balloon being disposed in sealingengagement with said support member for closing the inner end of saiddischarge passage, when the pressure within said balloon is less thansaid predetermined maximum.

, 3, An apparatus according to claim 9, wherein said support member isprovided with a flat surface, and said discharge passage comprises anelongated groove extending longitudinally of said flattened surface. I

4. An apparatus according to claim 9, wherein said support memberincludes a substantially. annularportion disposed adjacent the inner endthereof and positioned for sealing engagement .with the surrounding neckportion of said balloon, said annular portion being disposed inwardlyfrom the inner end of said discharge passage for preventingcommunication between said discharge passage and the interior of saidballoon when the pressure within sad balloon is below saidpredeterminedmaximum.

5. An apparatus according to claim 11, wherein said support I member hasa portion having a substantially truncated conical configurationdisposed within said neck portion of said balloon.

6. An apparatus according to claim 8, wherein said support meansincludes a substantially cylindrical support member disposed within andin sealing engagement with the neck portion of said balloon, saidsupport member having a plurality of circumferentially spaced,longitudinally extending grooves formed in the periphery thereof, andthe neck portion of said balloon having a plurality of inwardlyextending,v axially directed folds normally disposed within said groovesfor closing same to prevent flow of breathing gases therethrough whenthe pressure within said balloon is belowsaid predetermined maximum.

7. An apparatus according to claim 8, wherein said support meansincludes an elongated discharge member extending into the interior ofsaid balloon, said discharge member having said discharge passage meansextending therethrough, said discharge member having one end thereofpositioned'adjacent an end portion of said balloon opposite from theneckportion thereof, with said end portion of said balloon being normallymaintained in sealing engagement with said one end of said dischargemember for preventing communication between the interior of said balloonand said discharge passage means whenever the pressure within said.balloon is less than said predetermined maximum.

8. An apparatus according to claim 14, further including resilientlyurged engaging means disposed externally of said balloon and positionedfor engagement with the end portion of said ballobn for normallyresilientlymaintaining said end por-' tion in sealing engagement withsaid one end of said discharge member for preventing flow through thedischarge passage means whenever the pressure within said balloon isless than said predetermined maximum. I

9. A breathing apparatus comprising a storage balloon havinga neckportion defining an opening into the interior of said balloon, andsupport means at least partially disposed within said opening andsealingly engaged by said neck portion for closing said opening, saidsupport means having a flow passage extending therethrough for providingcommunication between the interior of said balloon and a locationdisposed externally of said balloon for permitting breathing gases to besupplied to and withdrawn from said balloon, the improvement whereinrelief means are provided for permitting external discharge of excessgases from said balloon during expansion thereof when the pressure ofthe gases within the balloon exceeds a predetermined maximum, saidrelief means including discharge passage means formed in said supportmeans for permitting discharge of said excess gases at a locationexternally of said balloon, said discharge passagemeans having an innerend adapted for communication with the interior of said balloon, andsaid balloon having a movable wall portion normally disposed inengagement with a portion of said support means for preventingcommunication between the interior of said balloon and the inner end ofsaid discharge passage means when the pressure within the balloon isless'than said predetermined maximum, whereby exceeding saidpredetermined maximumpressuring during expansion of said balloon causessaid movable wall portion to move out of sealing engagement with saidsupport means for permitting the excess gases to flow through saiddischarge passage means.

'10. A breathing apparatus according to claim 16, wherein said supportmeans includes a hublike support member disposed within and sealinglyengaged by the neck portion of said balloon, and said discharge passagemeans including a discharge passage formed in said support member withthe inner end of said discharge passage terminating adjacent theexternal periphery of said support member in the region surrounded bythe neck-portion of said balloon whereby said neck portion normallyprevents communication between said discharge passage and the interiorof said balloon, a part of said neck portion being radially expandableso as to move out of sealing engagement-with said support member topermit gases within the interior of said balloon to flow through saiddischarge passage when the pressure within said balloon exceeds saidpredetermined maximum.

11. A breathing apparatus according to claim 16, wherein said supportmeans includes an elongated tubular discharge member extending into theinterior of said balloon, said discharge member having anend thereofdisposed adjacent an end portion of said balloon opposite from said neckportion, said end portion of said balloon being normally disposed insealing engagement with said end of said tubular discharge member forpreventing communication between the interior UNITED STATES PATENTOFFICE CERTIFICATE OF CORRECTION Patent No. 3 599 634 Dated August l7,19 71 I. Inventor($) Soren Henrik Eng'lpqqnn It is certified that errorappears in the above-identified patent and that said Letters Patent arehereby corrected as shown below:

Column 7, in line 42 "claim 8" should read --claim l---, in line 55"claim 9" should read -claim 2---, in line 59 "claim 9" should read--claim 2--, in line 68 "claim 11" should read --claim 4-, and in line72 "claim 8" should 4 read -claim l--.

Column 8 in line 8 "claim 8" should read --claim l-, in line 20 "claiml4" should read --claim 7-, in line 57 'claim 16" should read -claim 9-,and in line 72 "claim 16" should read ---claim 9 Signed and sealed this21st day of March 1972.

(SEAL) AtteSt;

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents RM PO-105O (10- uscomm-Dc 60376-P69 U 5 GOVERNMENT PRINTlNGOFFICEI I969 O--35334

1. In a breathing apparatus having a one-way closed flow circuit and astorage balloon or bladder connected to the circuit for momentarilyaccumulating and storing herein the breathing gases discharged from apatient, means for adding a supplement, such as oxygen or an anestheticagent, to the gases stored within the balloon, whereby said gases in theballoon are then supplied to the patient, said balloon including a neckportion having an opening therein and support means disposed within saidopening for supporting said balloon, the edge of said balloon as definedby said opening being in engagement with said support means, and saidsupport means having opening means extending therethrough for providingcommunication between said circuit and the interior of said balloonwhereby breathing gases can be supplied to or withdrawn from saidballoon, the improvement comprising: relief means for permittingexternal discharge of excess gases from said balloon during expansion ofthe balloon when the pressure of the gases within the balloon exceeds apredetermined maximum; said relief means including discharge passagemeans formed in said support means for permitting discharge of saidexcess gases to a location external of said balloon, said dischargepassage means having an inner end adapted for communication with theinterior of said balloon; and said balloon having a movable wall portionnormally disposed in sealing engagement with a portion of said supportmeans for preventing communication between the interior of said balloonand the inner end of said discharge passage means when the pressurewithin said balloon is less than said predetermined maximum; wherebyexceeding said predetermined maximum pressure during expansion of saidballoon causes said movable wall portion to move out of sealingengagement with said support means for permitting the excess gases toflow through said discharge passage means.
 2. An apparatus according toclaim 8, wherein said support means includes a substantially cylindricalsupport member disposed within the neck portion of said balloon, andsaid discharge passage means including a discharge passage formed withinsaid support member and extending substantially therethrough, the innerend of said discharge passage terminating at the outer periphery of saidsupport member at a location which is spaced from the inner end of saidsupport member, and said neck portion of said balloon being disposed insealing engagement with said support member for closing the inner end ofsaid discharge passage when the pressure within said balloon is lessthan said predetermined maximum.
 3. An apparatus according to claim 9,wherein said support member is provided with a flat surface, and saiddischarge passage comprises an elongated groove extending longitudinallyof said flattened surface.
 4. An apparatus according to claim 9, whereinsaid support member includes a substantially annular portion disposedadjacent the inner end thereof and positioned for sealing engagementwith the surrounding neck portion of said balloon, said annular portionbeing disposed inwardly from the inner end of said discharge passage forpreventing communication between said discharge passage and the interiorof said balloon when the pressure within sad balloon is below saidpredetermined maximum.
 5. An apparatus according to claim 11, whereinsaid support member has a portion having a substantially truncatedconical configuration disposed within said neck portion of said balloon.6. An apparatus according to claim 8, wherein said support meansincludes a substantially cylindrical support member disposed within andin sealing engagement with the neck portion of said balloon, saidsupport member having a plurality of circumferentially spaced,longitudinally extending grooves formed in the periphery thereof, andthe neck portion of said balloon having a plurality of inwardlyextending, axially directed folds normally disposed within said groovesfor closing same to prevent flow of breathing gases therethrough whenthe pressure within said balloon is below said predetermined maximum. 7.An apparatus according to claim 8, wherein said support means includesan elongated discharge member extending into the interior of saidballoon, said discharge member having said discharge passage meansextending therethrough, said discharge member having one end thereofpositioned adjacent an end portion of said balloon opposite from theneck portion thereof, with said end portion of said balloon beingnormally maintained in sealing engagement with said one end of saiddischarge member for preventing communication between the interior ofsaid balloon and said discharge passage means whenever the pressurewithin said balloon is less than said predetermined maximum.
 8. Anapparatus according to claim 14, further including resiliently urgedengaging means disposed externally of said balloon and positioned forengagement with the end portion of said balloon for normally resilientlymaintaining said end portion in sealing engagement with said one end ofsaid discharge member for preventing flow through the discharge passagemeans whenever the pressure within said balloon is less than saidpredetermined maximum.
 9. A breathing apparatus comprising a storageballoon having a neck portion defining an opening into the interior ofsaid balloon, and support means at least partially disposed within saidopening and sealingly engaged by said neck portion for closing saidopening, said support means having a flow passage extending therethroughfor providing communication between the interior of said balloon and alocation disposed externally of said balloon for permitting breathinggases to be supplied to and withdrawn from said balloon, the improvementwherein relief means are provided for permitting external discharge ofexcess gases from said balloon during expansion thereof when thepressure of the gases within the balloon exceeds a predeterminedmaximum, said relief means including discharge passage means formed insaid support means for permitting discharge of said excess gases at alocation externally of said balloon, said discharge passage means havingan inner end adapted for communication with the interior of saidballoon, and said balloon having a movable wall portion normallydisposed in engagement with a portion of said support means forpreventing communication between the interior of said balloon and theinner end of said discharge passage means when the pressure within theballoon is less than said predetermined maximum, whereby exceeding saidpredetermined maximum pressuring during expansion of said balloon causessaid movable wall portion to move out of sealing engagement with saidsupport means for permitting the excess gases to flow through saiddischarge passage means.
 10. A breathing apparatus according to claim16, wherein said support means includes a hublike support memberdisposed within and sealingly engaged by the neck portion of saidballoon, and said discharge passage means including a discharge passageformed in said support member with the inner end of said dischargepassage terminating adjacent the external periphery of said supportmember in the region surrounded by the neck portion of said balloonwhereby said neck portion normally prevents communication between saiddischarge passage and the interior of said balloon, a part of said neckportion being radially expandable so as to move out of sealingengagement with said support member to permit gases within the interiorof said balloon to flow through said discharge passage when the pressurewithin said balloon exceeds said predetermined maximum.
 11. A breathingapparatus according to claim 16, wherein said support means includes anelongated tubular discharge member extending into the interior of saidballoon, said discharge member having an end thereof disposed adjacentan end portion of said balloon opposite from said neck portion, said endportion of said balloon being normally disposed in sealing engagementwith said end of said tubular discharge member for preventingcommunication between the interior of said balloon and the interior ofsaid tubular discharge member whenever the pressure within said balloonis less than said predetermined maximum.